Tridonic Gmbh Co. Kg

Wayne Bell

Deepak Makwana

Paul Dalby

Andre Mitterbacher

Jamie Kelly

Kevin McDermott

Simon Lecker

The invention relates to an isolated driver () for lighting means (), comprising: a primary circuit (), a secondary circuit (), an isolation barrier () separating the primary circuit () and the secondary circuit (), wherein a ground potential of the primary circuit () and a ground potential of the secondary circuit () are connected via a capacitor (), and a control circuit () on the secondary side (), monitoring a current to/from the capacitor () to the ground potential of the secondary circuit () and issuing a mains () failure signal in case the current does not meet predefined conditions, preferably in case no such current is detected.

Isolated driver for lighting means

The invention relates to an operating device () for operating lighting means, in particular LEDs, comprising: a potential-isolated clocked converter (), having a transformer (T), which has a primary winding (N) and a seconding winding (N), and having a controllable switch (M) arranged on the primary side, wherein the converter () can be supplied with a supply voltage converter (); means () for directly or indirectly sensing the output voltage (Vout); and a control unit (ST) for controlling the switch (M), wherein the secondary current (I) through the secondary winding (N) linearly drops, starting from a position value (Imax), which the switch (M) is switched off, wherein the control unit (ST) is designed to adaptively sense a discharge duration (Tdischarge) between a switch-off of the switch (M) and a subsequent drop in the secondary current () to zero in order to control the secondary current (I).

LED driver

In a first aspect, the invention provides an LED converter, comprising: a resonant converter with a switching regulator, preferably a clocked half-bridge converter, a galvanic barrier, the primary side of which being supplied by the switching regulator and the secondary side of which being arranged for providing directly or indirectly power to terminals for connecting one or more LEDs, a control circuit on the primary side of the galvanic barrier of the resonant converter, a sensing means on the secondary side of the galvanic barrier sensing a secondary side electric parameter indicative of an LED load, when connected to said terminals, a feedback path from the sensing means to the control circuit adapted to feedback the secondary side electric parameter from the secondary side of the galvanic barrier to the primary side of the galvanic barrier, wherein in case no LED string is connected to the LED converter, the control unit is adapted to cyclically control a switching frequency of switching regulator switches, in particular switches of the clocked half-bridge, from a high frequency to a lower frequency, and to monitor whether the secondary side electric parameter reaches a predetermined threshold value, and to, in case the predetermined threshold value is reached, deactivate the switching regulator switches and to activate a voltage protection switch to pull the secondary side electric parameter to ground.

Lighting means insertion detection

A power factor correction circuit includes an inductor L1, a diode D1, a switch Q3 and a controller. An input voltage Vis applied to the inductor L1 which is cyclically discharged through the diode D1 by the operation of the switch Q3. The switch Q3 is controlled by the controllerwhich varies the on period of the switch Q3, during which the inductor is charged, for adjusting an output voltage Vtowards a target value V. The method includes obtaining an indication of the inductor L1 reaching a discharged state in response to the switch being in an off state. The controllermonitors at least one of the switch on period Tand the switch off period Tto identify when the input voltage Vis an alternating voltage AC input, and when it is likely to be a non-alternating voltage DC input. When a non alternating voltage is detected, steps may be taken to reduce interference.

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Durham, United Kingdom

Wayne Bell